WhatsApp Cofounder Discussion on Joining Facebook

Brian Acton still hasn't fully come to terms with the idea of his new life as a a billionaire and Facebook employee.

Acton, one of the two cofounders of WhatsApp, opened up about his personal feelings on the pending Facebook acquisition in his first speaking engagement ever at StartX, a startup incubator affiliated with Stanford University, on Wednesday night.

"More than anything, you are somewhat numb," Acton said of the negotiation process with Facebook. "You are dumbstruck as to what's going on. You have this flotilla of lawyers around you. And it was a lot of lawyers, I'll tell you that. Ninety-six hours of being in conference rooms with lawyers non-stop."

He continued: "By the end of it you're just numb. You're just trying to sort of grasp it all, and I don't think I really do grasp it all just yet. I think that it will hit me in stages. It's going to change my life, I know that. I'm looking forward to it, but it also with some apprehension.

Acton still has some time to try and grasp the situation. Facebook agreed to acquire for $19 billion in February. The deal was approved by the Federal Trade Commission in the U.S., but Facebook has reportedly asked the European Union to review the deal.

During the wide-ranging hour-long interview, Acton explained why the WhatsApp team refrained from doing press (it's all about "focus," he says, the real "F-word" at the company), his thoughts on Facebook CEO Mark Zuckerberg ("He's done far more with his company than I ever will ... I don't know when this guy sleeps") and why WhatsApp opted to sell rather than pursue a public offering one day.

"I think we hit a point in our lifetime of the company when we were either going to be acquired or have to go public," Acton said. "There's far more pain in going public. And Mark, by the way, already did it. So kudos to the guy for doing it. He had the energy to do it, he had the stamina do it. I don't know if I personally had that stamina."

Talks between WhatsApp and Facebook "got real real" in early February, according to Acton, when Zuckerberg "put a number in front of us."

To those who worry that WhatsApp might now give over its data on users to Facebook, Acton had a simple response: there really isn't much data to give.

"It's not like we're going to, on day one, send all this data over to Facebook," he said. "And by the way, we don't have any data. People don't really understand this, but we don't have much beyond a phone number to work with."

Ultimately, he stressed that Facebook and WhatsApp had agreed to a "model of independence," which will allow WhatsApp to continue business as usual, just with more resources as its disposal. Or, as Acton put it in what was probably the most colorful moment in the interview, "We don't necessarily look at it from the perspective that we're going to get swallowed by the Borg."